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No. 750,497. PATENTED JAN.'26, 1904, E. A. SPERRY.

SYSTEM OF ELECTRICAL GENERATION, DISTRIBUTION, AND CONTROL.

APPLICATION FILED DEC. 5, 1902.

N0 MODEL. 5 SHEETS-SHEET 1.

PATENTED JAN. 26, 1904.

E. A. SPEERY. SYSTEM OF ELEGTRIGAL GENERATION, DISTRIBUTION, AND CONTROL.

APPLIOATION FILED DEC. 5, 1902.

NOMODEL.

vfillun "IM Inventor.-

I? 5 /W/@Q .No. 750,497. PATENTED JAN. 26, 1904. E. A. SPERRY.

SYSTEM OF ELECTRICAL GENERATION, DISTRIBUTION, AND CONTROL.

- APPLICATION FILED DEG. 5, 1902. no MODEL. 5 SHEETS-SHEET s.

PATENTED JAN. 26, 1904.

E. A. SPERRY.

SYSTEM OF ELECTRICAL GENERATION, DISTRIBUTION, AND CONTROL.

APPLICATION FILED DEC. 5, 1902.

5 SHEETS-SHEET 4.

N0 MODEL.

No. 750,497. PATENTED JAN. 26, 1904. E. A. SPERRY. SYSTEM OF ELECTRICAL GENERATION, DISTRIBUTION, AND CONTROL.

APPLICATION FILED DEC. 5. 1902.

N0 MODEL. 5 SHEBTSSHEET 5.

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ms Nsnms PETERS c0. wo'ro umcw wAswmuYow. u c

Patented January 26, 1904.

UNITED STATES PATENT OFFICE.

ELMER A. SPERRY, OF CLEVELAND, OHIO, ASSIGN OR TO NATIONAL BAT- TERY COMPANY, OF JERSEY CITY, NEW JERSEY, AND BUFFALO, NE YORK, A CORPORATION OF NEW JERSEY.

SYSTEM OF ELECTRICAL GENERATION, DISTRIBUTION, AND CONTROL.

SPECIFICATION forming part of Letters Patent No. 750,497, dated January 26, 1904.

Appiieation filed December 5, 1902. Serial No. 134,035. (No model.)

To all whom it may concern.-

Be it known that I, ELMER A. SPERRY, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Systems of Electrical Generation, Distribution, and Control, of which the following is a specification.

This invention relates to systems and apparatus for the generation, distribution, and control of electric current, and has been developed more especially with a view to the solution of difiiculties incident to variations in speed of the source of power by which the generator is driven.

The particular application of the invention with reference to Which it was developed and in which it finds its concrete expression is railway-car lighting, in which current is generated through the movement of a car or train, the generator being ordinarily driven from a car-axle. In such an application of the invention provision should be made to maintain uniform strength of current notwithstanding considerable variation in the speed of the car. The effect upon a system of a reversal of the direction of movement of the car should be anticipated and accommodated. Provision should be made for discontinuing the operation of the generator under conditions which are unfavorable to the continued generation of current through the movement of the car, as when the train approaches a terminal and takes the short-radius curves, switches, and crossovers common in a terminal yard. The automatic supply of current to the lighting-circuit of the car when the speed falls below a predetermined rate should be provided for. The medium through which the automatic regulation and control of the various parts of the system are effected should be of such a character as to be substantially unaffected by considerable variations in temperature and the other,conditions of use. The different various devices should be so constructed as to be substantially unaffected by the vibrations and other conditions of use, and in general the system should be adapted to overcome difficulties incident to the character of the source of power and to the condititions under which the system is used.

It is the object of this invention to meet the various requirements indicated above and to produce a system which will give thoroughly satisfactory results under all conditions of use, either for the lighting of railway-cars or for other analogous purposes.

It will be obvious that the general object can be attained and the general features of construction and arrangement can be embodied by and in specific structures which differ more or less in detail. One of such embodiments will be particularly described hereinafter with reference to the accompanying drawings, in which it is illustrated, and in order that the functions of the several mechanical parts may be more readily comprehended a general description of such embodiment of the invention without reference to the drawings will now be presented.

The generator or dynamo is frictionally driven, as by a belt, from one of the car-axles, and in order that the slip of the belt may be taken advantage of to assist in the regulation of the electromotive force through regulation of the speed of the dynamo a belt-tightener is provided for the purpose of slackening or tightening the driving-belt. The action of the belt-tightener to slaclzen or tighten the belt is controlled by the pressure of a suitable fluid medium, preferably an oil which will resist low temperatures, the pressure being developed by the action of a pump driven by a motor which is in circuit with the dynamo or batteries supported thereby. A valve in the pipe system may be suitably controlled, as by a solenoid or other electromagnetic device in circuit with the dynamo, to vary the pressure at the point where it performs its work in controlling the belt-tightener, whereby any variation in the voltage of the current shall effect the movement of the belt-tightener to tighten or slacl en the belt, and thereby to correct the variation in the voltage and restore it to the normal. The motor for driving the pump is also subject to the control of the pressure of the fluid medium, so that its operation shall cease when the pressure rises above a predetermined degree and shall be resumed automatically when the pressure falls below a predetermined degree. To compensate for variation in the electrical translating devices, as in the number of lights in circuit, so that the voltage of the current supplied to the remaining lights shall remain substantially uniform, and to compensate for variations in voltage of battery or dynamo, suitable resistance is in eluded in the circuit and means are provided for throwing in or out more or less of such resistance, such means being operated by the pressure of the fluid medium and controlled by the action of a solenoid or other electromagnetic device included in circuit with the lamps. A storage battery is to be included in the circuit in order that the necessary lighting-current may be provided when the car is station ary or the speed of the car falls below a predetermined minimum.

In the accompanying drawings, wherein is illustrated the particular embodiment of the invention chosen for explanation, Figure l'is an outline, in side elevation and partlybroken out, of a railway-car equipped with the invention embodied in a lighting system. Fig. 2 is a diagrammatic view illustrating the general relation of the several mechanical and electrical elements of the system in the same application thereof. Fig. 8 is a view, partly in elevation and partly in vertical section, illustrating the means for controlling the slip of the belt by which the dynamo is driven. Fig. & is a detail view, on a larger scale, of a portion of the belt-tightener with the dynamo and its driving-pulley. Fig. 5 is a view in vertical section of the solenoid and valve operated thereby for controlling the pressure upon the piston shown in Fig. 3. Fig. 6 is a view in vertical section on the plane indicated by the line 6 6 of Fig. 8, showing the pump. Fig. 7 is a view in vertical section on the plane indicated by the line 7 7 of Fig. 8, illustrating the device for starting and stopping the pump automatically. Fig. 8 is a horizontal section on the plane indicated by the line 8 8 of Figs. 6 and 7. Fig. 9 is a view in vertical section, illustrating the mechanical devices for operating the rheostat. Fig. 10 is a view in hori- Zontal section on the plane indicated by the line 1O 10 of Fig. 9. Fig. 11 is a view in vertical section of the solenoid and the valve operated thereby for controlling the pressure upon the plunger shown in Fig. 9. Fig. 12 is a top plan view of the parts shown in Fig. 11. Fig. 13 is a detail plan view showing the devices for slackening the belt for driving the dynamo when the car strikes a curve of short radius. Fig. 1a is a detail view in section on the plane indicated by the line 14 1a of Fig. 13, but on a somewhat larger scale. Fig. 15

is a detail view in section on the plane indicated by the hne 15 15 of Fig. 13 looking toward the right and on a somewhat larger scale.

The dynamo (indicated at a.) may be of any suitable construction and is supported beneath the car-floor or in any other convenient location. At one or at each end of its shaft (4 it is provided with a fly-wheel a that the storage of energy therein may contribute to the steadiness of the current generated and especially in the particular application of the invention illustrated may overcome in large measure that flapping of the drivingbelt which in car-lighting systems of this class has been found to take place in considerable degree because of the peculiar conditions of operation and to occasion marked fluctuations in the lamps, such fluctuations having such frequency and being so erratic that the control ling mechanism cannot of itself overcome them altogether.

So far as the general features of this invention are concerned the source of power may be regarded as unidirectional, so that factors incident to the frequent reversal or reciproeating movement of the source of power may be disregarded; but upon consideration of the peculiar conditions of the operation above referred to, such as the constant springing of the car-truck and of the car-body, it will be seen that the ordinary flapping of a drivingbelt which is induced by such conditions creates very serious difficulties in the way of the successful operation of an axledriven carlighting system. The provision of the flywheel, in combination with the dynamo, beltdriven from the axle, largely eliminates the fluctuations of the dynamo due to such flapping of the belt and is therefore an important consideration. The fly-wheel at one end may be combined with the drivingilley a", over which passes the driving-belt a from the d riving-wheel b on the car-axle.

For the purpose of controlling the speed, and therefore the electromotive force, of the dynamo through the friction of the driving means a belt-tightener is provided to act upon the belt, being itself controlled by devices presently to be described. The belt-tightener illustrated in the drawings, particularly in Figs. 3 and 4, is designed with especial reference to the particular application of the invention herein referred to, being so arranged with reference to the driven pulley u. of the dynamo as to give the belt as much grip as possible upon the pulley, thereby making it possible to employ a pulley of small diameter, so that the effective speed of the dynamo will be attained, at a moderate speed of the car and being further arranged to act, as is desirable, upon the slack side of the belt whether 0 adapted to rest against one side of the belt. To the frame 0 is pivoted an arm 0 also having a pin or stud 0 carrying an idler 0", adapted to rest against the other side of the belt. It will be obvious that the provisions for lubricating these idlers must be adapted especially to the severe conditions under which the idlers operate, and in Fig. 4: of the drawings are shown such specially-designed lubricating devices. As there represented, the pin or stud c (and the following description applies equally well to the devices for supporting and lubricating the idler 0 is chambered, as at c, and bears at its extremity an oil-cup 0 which may be of ordinary character. The idler c is likewise chambered, as at 0 Between the stud 0 and the idler c are interposed sleeves c" and 0 which do not meet, the sleeve 0 at the outer end of the stud being pressed toward the other and held by suitable lock-nuts 0 both of said sleeves having flanges between which the idler c is held. Suitable openings .are provided through the wall of the stud e and through the inner wall of the idler c to permit the passage of oil from one to the other between the ends of the sleeves c and 0 and wicking or other suitable absorbent is placed in the cavities c and 0 This construction protects the bearings from the entrance of dust, provides for the retention of a considerable quantity of lubricant, and insures the proper distribution of such lubricant.

The mechanical devices for acting upon the belt-tightener to slacken or to tighten the belt are mounted upon the frame 0 and are connected to the arm 0 and are adapted to in crease or diminish the distance between the two idlers c and 0 If the belt is running in one direction, one of the idlers, as the idler o as indicated in Fig. 8, will be supported by the taut side of the belt, while the other idler, as 0 will take up the slack of the slack side of the belt; but if the direction of movement of the belt be reversed the idler a will then be supported by the taut side of the belt and the idler 0 will take up the slack of the belt. This arrangement, as indicated hereinbefore, not only provides for an increase of the grip of the belt on the driven pulley, but since it substantially reduces the unsupported length of the slack side of the belt also reduces the liability of the slack side of the belt to flap, and consequently to vary the strength of the current.

One object of the invention being to provide for the operation of the belt-tightener by a fluid medium, the mechanical devices for operating the belt-tightener comprise a cylinder (Z, which is fixed upon the oscillating frame 0, as indicated above, and a piston (Z in said cylinder and connected by suitable link (Z with the arm 0 the fluid medium under pressure from a suitable source being admitted to the cylinder behind the piston. Oil of a suitable quality placed under elastic pressure by a l suitable pump is the most satisfactory medium for the transmission of the required power to the mechanical element, such as the piston d, by which the tightening of the belt is effected, lending itself most readily to the peculiar requirements of the case, the belt-regulating devices thus becoming sensitive and quickly responsivein operation, while acting with certainty under conditions of constant and excessive vibration and of widely-varying temperatures. Furthermore, such devices are readily controlled through variations of the voltage of the current produced by the dynamo, so that such current is generated as required and remains substantially uniform notwithstanding considerable variations in the speed of movement of the car. The cylinder (Z ac cordingly is connected by a suitably pipe system including sections (Z and d, which are movable to accommodate the movement of the cylinder with the frame 0, and a fixed section (P, with an oil-pressure tank (Z and a pump a, operated by a motorf, which is in circuit with the translating devices and the storage battery, hereinafter referred to. The tank (Z may be an ordinary tight tank having a single in: let for connection with the pipe system d" and preferably contains a volume of air which acts as an elastic cushion for the oil which is delivered by the pump e. The latter is placed 9 1n convenient relation to an oil-pan which contains the supply of oil and receives the oil through the return-pipes from the several actuating devices, the pump being preferably mounted above the oil-pan at any convenient point within the car and being of ordinary construction comprising a reciprocating plunger 0, an inlet-valve a and an outlet-valve the discharge being connected with the pipe system d. The plunger 0 may be connected by a pitman a with a crank or crank-pin a, carried by the shaft of a gear (2 which is in mesh with a driving-pinionf on the shaft of the small motor provided for the operation of the pump.

Means are provided whereby the operation of the pump shall bedependent upon the pressure on the fluid medium, the pump being automatically thrown out of operation when the pressure rises above a predetermined degree and also thrown into operation when the pressure falls below a predetermined degree. It is desirable to provide for a direct control of the pressure on the piston-head (Z by variations in the voltage of the current. To this end a solenoid 71/ is included in circuit with the dynamo. Its core it is statically balanced, being connected by a lever 72. with a counterweight if, so that the core shallnot be affected by the vertical vibrations of the car, and also with an adjustable spring b", which opposes the pull of the solenoid upon the core. The core of the solenoid controls a valve (Z interposed in the pipe system, by means of which admission of oil to the cylinder (Z is regulated &

and by which the oil in the cylinder may be in part released and permitted to return to the oil-pan, so that the belt may slacken. As shown, the valve comprises a plug or stem (Z turned down, as at (P, to form a passage between the head (Z and the body of the valve. The valve-chamber has a port (Z communicating with the pressure-tank, a port (Z communicating with the cylinder (Z, and a port (Z communicating with the oil-pan through a return-pipe cl. The valve is shown in its normal position, the port (Z being closed. If now the voltage of the current increases, the core will be raised so that the head d of the valve shall be moved to establish connection between the port (Z and the port (Z thereby relieving the pressure beneath the piston d in the cylinder (Z and permitting the belt to slacken, and therefore to slip, whereby the speed of the dynamo is reduced. If, on the other hand, the voltage of the current decreases, the spring lt draws down the core 71., thereby moving the valve-plug (Z to establish communication through the channel (Z between the ports (Z and (Z thereby permitting more oil to pass into the cylinder cl, and thereby to tighten the belt and increase the speed of the dynamo.

It will be understood that the ordinary finewire winding [L5 of the solenoid h is included in a shunt from the main circuit of the dynamo. Under some circumstances, as when a great quantity of current is flowing over the circuit, it is desirable to assist the fine winding of the solenoid in its action upon the core to open the valve and relieve the pressure behind the belt-controlling piston in order that the dynamo may be checked and abnormal overloading and consequent burning out prevented. Accordingly a winding it of coarse wire is first laid up and down about the sleeve of the solenoid and is connected in series with the armature-windin g of the dynamo. A resistance may be thrown across the connections of this coarse winding, and when the quantity of current rises to a predetermined degree, for which the windings of the solenoid and the resistance are duly proportioned, the coarse winding will assist the fine winding and insure the prompt opening of the valve and the consequent checking of the dynamo.

Vhcther any other device be employed to regulate the pressure in the cylinder (Z, as above described, or not, it is desirable to provide means, as above suggested, whereby the pump shall be stopped whenever the pressure on the fluid medium increases above a predetermined maximum and shall be started again whenever the pressure falls below a predetermined minimum. To accomplish this, a pressure-relay device, as shown in Fig. 8, is employed. This device comprises a cylinder 2', having a punger '11 moved in one direction by an adjustable spring 2' The cylinder 6 is in communication with the pipe system (P, so

that the plunger 71 is shifted by variations in the pressure, and the plunger controls a valve (Z which may be in all respects the same as the valve (Z the same reference-letters being employed to indicate like parts. The port (Z of the valve (Z is in communication with the pressure-tank, the port (Z is in communication with the return-pipe d, and the port cl is in communication with a cylinder 7:, in which is a plunger k, adapted to be moved in one direction by the pressure in the cylinder and in the opposite direction by a spring The stem 7:: of the plunger is operatively connected with a switch 70 in the branch of the circuit which includes the motor f, the switch being opened when the plunger it" moves downward under the influence of the spring 715* and being closed as it is moved upward by the pressure of the fluid medium in the cylinder 70. It will now be understood that when the pressure in the pressure-tank increases above the predetermined maximum the plunger a" will be moved upward against the spring '5 thereby permitting the pressure beneath the plunger L to be relieved by the movement of the valve-plug (Z which establishes communication between the ports (Z and Cl. On the other hand, if the pressure in the system falls below the predetermined minimum the plunger a" will descend against the reduced pressure in the cylinder 2', moving the valve-plug (Z downward to establish communication between the ports (Z and d, thereby admitting the fluid medium to the cylinder 7: and raising the plunger 71; to close the switch A" and start up the pump again. A non-centering spring if is connected to the switch to retain the switch and the plunger in their extreme positions, lost motion being provided for between the plunger and the switch, as by a slotand-pin connection, as at 71, to facilitate the quick movement of the switch.

In order that the voltage of the current supplied to the lamps shall be substantially uniform, notwithstanding variations in the n umber of lamps in use or in the current supplied by the dynamo or batteries, or both, and especially to utilize the full range of the battery voltage, it is desirable to include in the lampcircuit a variable resistance, the amount of resistance included being controlled automatically. As represented in the drawings Figs. 2, 9, 10, 11, and 12, the device comprises an ordinary variable resistance 6, a movable contact-arm m, and mechanical devices electrically controlled and actuated for shifting the arm 721. As represented in the drawings, a solenoid a is included in the main circuit, while its core a is statically balanced, being connected by a lever n? with a counterweight wf" in order that the core may not be affected by vibrations and with an adjustable spring at, which opposes the action of the solenoid. The core is opcratively connected with a valve (1, which is in all respects similar to the valve 0Z heretofore described. The parts of the valve al are indicated by like letters of reference and no detailed description of the valve is necessary. The port (Z is in communication with the pressure system and the port (Z with the return-pipe system (Z while the port (Z is in communication with a cylinder 0, in which is disposed a plunger 0. A rack 0 carried by the plunger, engages a pinion 0 on the shaft 0', which carrice the movable resistance-arm m. A coilspring 0 may be applied to the shaft 0 to oppose the pressure in the cylinder 0 and restore the parts to normal position when the pressure therein is reduced. It will be understood that when the voltage increases the core at will be drawn up and the valve 6 will be operated to connect the cylinder 0 with the return-pipe system (i through the ports (Z and ti, thereby permitting the plunger to descend and the arm m to be moved to include more resistance in the lamp-circuit, and that if the voltage falls the spring a will cause the core to move downward, actuating the valve al to admit pressure to the cylinder 0 through the ports cZ and (Z thereby moving the plunger and the arm on in a direction to reduce the amount of resistance included in the circuit.

In the application of the invention herein illustrated and explained it is obviously undesirable that the dynamo should continue to rotate when the speed of the train is reduced below the predetermined minimum, as when it is approaching a terminal station. Upon the running track between stations if it should happen that the train is slowed down the pressure of the fluid medium can be relieved by the attendant in order to release the belt-tightener and slacken the driving-belt. When the train slows down, however, at the approach to a terminal station, the short radius of the switch curve can be taken advantage of to effect the release automatically, at the same time making it possible for the parts to return automatically to their normal working relation somewhat slowly, so that the operation of the dynamo will be resumed soon after the train has passed the last curve of short radius, but will not be resumed while the train is passing from one to another of a succession of curves of short radius. The disalinement or lateral oscillation of the truckframe (indicated at p in Figs. 13, 14:, and 15) is taken advantage of to efl'ect the release of the pressure of the fluid medium behind the piston which controls the belt-tightener, so that the belt can slacken. A relief-valve (Z of large discharge capacity is located at a convenient point in the pipe system between the reservoir and the pan g. As clearly indicated in Fig. 14, the discharge from the valve is much larger than the inlet for the purpose of permittinga quick release of pressure while the return of the parts to their normal working relation through the throttling action of the valve (Z or the action of the pump and the pressure in the reservoir will be comparatively slow. The stem of the valve is operatively connected with a rock-shaft q, the arm of which may have attached a spring to hold the valve normally closed. oscillated by the lateral oscillations of the truck p and for this purpose may have at its end a double arm 9, in each end of which is a pin g". Strikers and q are mounted upon the truck in position to cooperate respectively with the pins 9 as the truck swings to one side or the other, rocking the shaft in such direction as to open the valve (Z thereby relieving the pressure behind the piston (Z in the cylinder (Z and permitting the belttightener to slacken the belt, so that it will no longer drive the dynamo.

It will be understood that the device just described is provided, not because the existence of the short-radius curves in the track of itself renders desirable an automatic stopping dynamo, but because the existence of such short-radius curves generally requires the slowing of the speed of the train, and consequently the slowing of the speed of the dynamo, to such an extent that it is desirable to discontinue the operation of the dynamo until the speed rises again. The effect of such short-radius curves, however, in producing lateral oscillations of the car-truck is taken advantage of to bring about automatically the stopping of the dynamo. It is obvious that curves of the ordinary radius will not bring about such stopping of the dynamo and that it is only curves of short radius which will oscillate the trucks far enough to effect the release of the belt-tightener through the operation of the relief-valve (Z A storage battery 0" is arranged to be included in circuit to maintain the lights when the car is stationary or moves at a speed less than the predetermined minimum. It may be recharged from the dynamo, and provision is made whereby the dynamo shall be cut out when the current generated is less than supplied by the battery. To this end a switch s, having a member in each leg of the main circuit, is arranged to be controlled by a differential magnet 2,, the armature t of which is operatively connected with the switch and has attached a spring 6 to open the switch when the armature is released by the magnet. One set, 25 of the coils of the magnet is included in a shunt from the main circuit and energizes the magnet to hold the armature normally up with the switch closed. The other set, 25', of the coils of the magnet is included in one leg of the main circuit in series with one of the switch members, the coils being wound in the same direction as those of the set 25 Thus if the electromotive force of the current from the battery exceeds that of the current from the dynamo the rush of current backward The shaft isthrough the coils 2? will neutralize the effect of the coils 25 upon the core of the magnet and permit the armature to drop. hen the electromotivc force of the dynamo is increased sufliciently, the coils t included in the shunt, will energize the magnet sufliciently to again attract the armature and restore the connection between the dynamo and the lamp-circuit.

The operation of the system will be understood i'rom the foregoing description without further explanation.

Some of the broader features of improvement herein disclosed, as well as some of the details, are not herein claimed, since they are the joint invention of the present applicant and another and will be made the subject of another application about to be filed.

I claim as my invention 1. In an electriccar-service system, the combination of a car-axle, a generator, driving means including a belt between the car-axle and the generator, a belt-tightener adapted to act upon either side of the belt and means whereby the belt-tightener is carried to take up the slack of the slack side of the belt when the direction of movement of the car is reversed.

2. In an electric-car-serviee system, the com bination of a car-axle, a generator, driving means including a belt between the car-axle and the generator, a belt-tightener having two parts arranged for cooperation with the two sides of the belt respectively, and means acting upon both parts to press them against opposite sides of the belt, whereby either part takes up the slack of the slack side of the belt when the direction of movement of the car is changed.

3. The combination with a power source and an electric generator relatively movable in position, of a driving-gear between the power source and the generator, and devices actuated by variations in relative position, of the power source and the generator to control the engagement of said driving-gear.

l. The combination with a power source and an electric generator relatively movable in position, of a driving-gear between the power source and the generator, a pressure device to regulate the engagement of said driving-gear, and devices actuated by variations in relative position of the power source and the generator to control said pressure device.

5. The combination with a power source and an electric generator relatively movable in position, of a driving-gear between the power source and the generator, a fluid-pressure device to regulate the engagement of said driving-gear and devices actuated by variations in relative position of the power source and the generator to control said fluid-pressure device.

6. The combination with a power source and an electric generator relatively movable in position, of a driving-gear between the power source and the generator, a l'luid-pressure device to regulate the engagement of said driving-gear, means to supply fluid under pressure, a valve having a relatively large discharge to relieve the pressure in said device and devices actuated by variations in relative position of the power source and the generator to open said valve.

7. The combination with a power source and an electric generator relatively movable in position, of a belt between the power source and the generator, a belt-tightener, and devices actuated by variations in relative position, of the power source and generator to control said belt-tightener.

S. The combination with a power source and an electric generator relatively movable in position, of a belt between the power source and the generator, a belt-tightener, a fluidpressure device to control said belt-tightener, a valve to control said fluid-pressure device and devices actuated by variations in relative position of the power source and the generator to control said valve.

9. In an electric-car-service system,the combination of a relatively fixed generator, an oscillating truck-frame, driving means between the car-axle and the generator, and devices actuated by the oscillations of the trucki'rame to control the engagement of the driving means.

10. In an electric-car-service system, the combination of a relatively fixed. generator, an oscillating truck-frame, a car-axle, driving means including a belt between the axle and the generator, a belt-tightener, and devices actuated by the oscillations of the truck-frame to control the belt-tightener.

11. In an clectric-car-service system, the combination of a relatively fixed generator, an oscillating truck-frame, a car-axle, driving means including a belt between the axle and the generator, a belt-tightener, a fluid-pressure device to control the belt-tightener, a valve to control said fluid-pressure device, and means actuated by the oscillation of the truck-frame to operate the valve.

12. The combination of a generator, driving means, controlling devices for said driving means, translating devices in circuit with the generator, and an electromagnetic device to actuate said controlling devices, said electromagnetic device having one winding in multiple with the translating devices and another winding in series in one side of the circuit, with a resistance bridged across the terminals of said last-named winding, whereby said last-named winding may assist the firstnamed winding to actuate said controlling devices.

13. The combination of a generator, translating devices in circuit with the generator, a switch between the generator and the translating devices, a storage battery in circuit ITO with the translating devices, said generator being connected with said storage battery and said translating devices through said switch only, and a differential magnet operatively connected with said switch, said magnet having one set of windings in multiple with the generator and the other set of windings con nected in series in one side of the circuit through the contacts of the switch, whereby said switch is opened when the electromotive force of the battery exceeds that of the generator and all connection between the generator and the storage battery and transmitting devices is interrupted.

14:. In an electric-car-service system, the combination of a generator, current-controlling devices, fluid-pressure devices to operate said controlling devices, a pump to supply fluid under pressure, a motor to operate the pump in circuit with the generator, a switch between the motor and the generator, means to operate said switch, and a non-centralizing device acting upon said switch to throw it quickly past its center of movement.

15. In an electric-car-service system, the combination of a generator, currentcontrolling devices, fluid-pressure devices to operate said controlling devices, a pump to supply fluid under pressure, a motor to operate the pump in circuit with the generator, a switch between the motor and the generator, a plunger operated by the fluid under pressure, and operatively connected with the switch, and a noncentralizing device acting upon said switch to throw it quickly past its center of movement.

16. In an electric-car-service system, the combination of a generator, current-controlling devices, fluid-pressure devices to operate said controlling devices, a pump to supply fluid under pressure, a motor to operate the pump in circuit with the generator, a switch between the motorand the generator, a plunger operated by the fluid under pressure and operatively connected with the switch, a lostmotion device in the connection between the plunger and the switch, and a non-centralizing device acting upon said switch to throw it quickly past its center of movement.

17. In an electric-car-service system, the combination of a generator, current-controlling devices, fluid-pressure devices to operate said controlling devices, a pump to supply fluid under pressure, a motor, a plunger subject to the pressure developed by the pump, means actuated by the plunger to control the pump, a second plunger subject to the pressure developed by the pump, and a valve operated by the second plunger to control the admission of the fluid under pressure behind the first plunger.

This specification signed and witnessed this 1st day of December, A. D. 1902.

ELMER A. SPERRY.

In presence of ANTHONY N. J ESBERA, M. A. BRAYLEY. 

